Table 2. Comparison of reported catalytic systems for the synthesis of 2-substituted 1,3-benzothiazoles.

Catalyst/System	Conditions	Time (h)	Yield	Ref.
Nano-BF3/SiO2	r.t, EtOH	25 min	90	53
Phosphonium acidic IL	Solvent-free, reflux, 120 °C	1 h	91	54
Cu(ii)-glycerol/MCM-41	r.t, EtOH	2.5 h	96	55
Fe3O4@SiO2@Cu–MoO3	r.t, EtOH	2 h	98	56
CSA	r.t, EtOH : H2O (1 : 1)	1 h	91	57
CuO NSs	r.t, EtOH : H2O (1 : 1)	10 min	98	This work